Estimation of Multiple Faults in Hydrostatic Wind Turbines using Takagi-Sugeno Sliding Mode Observer with Weighted Switching Action

This paper presents the estimation of multiple actuator faults based on variable structure observer for nonlinear systems in Takagi-Sugeno form. The discontinuous observer term responsible for establishing the sliding motion is modified in such a way that the individual system output errors can be weighted using appropriate gains. This approach allows to estimate multiple actuator faults with widely varying signal magnitudes. The advantages of this method are shown by means of wind turbines with hydrostatic transmission. The objective is a simultaneous estimation of faults in the hydraulic displacement unit and the generator torque. Simulation results demonstrate the efficiency of the present estimation technique.